Electric-arc lamp.



PATBNTED DEC. 18, 1904.

L. E. SAPFORD.

ELECTRIC ARC LAMP.

APPLICATION FILED AUG. 19. 1903. RENEWED MAY 18, 1904.

2 SHEETS-SHBET 1 81 \NV ENTOR L 9 m 7 W m N M d PATENITED DEC. 13, 1904.

L. E. SAFPORD.

ELECTRIC ARC LAMP.

APPLIOATION FILED AUG.19, 190a. RENEWED MAY 18, 1904.

2 SHEETS-SHEET 2.

N0 MODEL.

W ITNESSES:

NVENTOR Patented December 13, 1904.

UNITED STATES PATENT OEEIcE.

LAFAYETTE E. SAFFORD, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR TO THE KEYSTONE ELECTRIC AND MANUFACTURING CO., OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 777,146, dated December 13, 1904. Application filed August 19, 1903. Renewed May 18, 1904. Serial No. 208,563. (No model.)

To all whom. it Hour/y concern.-

Be itknown that I, LAFAYETTE E. SAFFORD, a resident of Allegheny, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Arc- Lamps; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to arc-lamps.

One of the objects of my invention is to provide an electromagnet for use in connection with arc-lamps in which the magnet is so constructed as to withstand great heat and prevent the burning out of the same, while at the same time the coil is so inclosed as to greatly increase the efiiciency of the lamp.

Another object of my invention is to provide for the location of the dash-pot, so as to reduce the length of the lamp and permit the use of a dash-pot of greater area and prevent all friction. v

To these ends my invention comprises the novel features hereinafter set forth and claimed.

To enable others skilled in the art to make and use my invention, I will describe the same more fully, referring to the accompanying drawings, in which Figure 1 is a sectional elevation of my improved arc-lamp. Fig. 2 is a cross-section on the line 2 2, Fig. 1. Fig. 3 is across-section on the line 3 3, Fig. 1. Fig. 4c is an enlarged detail of the upper portion of the electromagnet. Fig. 5 is a cross-section on the line 5 5, Fig. 4. Fig. 6 is a portion of the continuous spiral coil of the electromagnet. Fig. 7 is a perspective view of one of the insulatingdisks. Fig. 8 is an enlarged detail of the construction of the dash-pot piston, and Fig. 9 is an enlarged detail view of the spiral conductor for conveying current to the carbon.

Like numerals indicate like parts in each of the figures.

In the drawings the numeral 2 designates the top or cap of the lamp, provided with suitable binding-posts 3, properly insulated, and a plug 41, forming a support by means of which the lamp may be suspended. Below closure for the resistance-holder 6 and the I electromagnet 7, together with other necessary parts. As the resistance-holder forms no part of my invention, I have not deemed it necessary to describe the same in detail or the manner of supporting it, &c.

A brass tube 8 is supported within the socket 9 in the cap 2, said tube having the thimble 10 at the upper end thereof, and engaging with said thimble by pin-and-slot connection, so it cannot turn, is the inner tube 11, closed by the head 12. ithin the tube 11 is the bushing 13 for supporting the upper carbon 1 1, said bushing being provided with a projection engaging a slot in tube 11 and with the pin 15. A spiral conductor 8 is contained within the tube 8, said conductor preferably being formed of a flat strip of copper wound edgewise and adapted to elongate or contract, according as the carbon is lowered or raised. This conductor is secured to the cap 9 by a suitable screw and to the plug 12 of the inner tube 11. A second spiral conductor 11 of the same construction is secured to the plug 12 and at its lower end to the carbon bushing 13. This provides a flexible conductor which will adapt itself readily to the position of the carbon and when compressed coils in a regular manner, so as to be very compact.

A split ring 16 encircles the tube 8 at its lower end, said ring being provided with the binding-screw 17, by means of which said ring is securely held in position on the tube 8. The electromagnet 7 is supported by this ring 16, and said magnet is construct-ed in the following manner: There is a bottom plate 18, provided with a properlyinsulated terminal 19, to which the lead-wire 20 is connected. The coil of the magnet is supported upon the plate 18, and said coil consists of a spirally-wound copper ribbon 21, and interposed between each winding or layer of said coil is a disk of insulating material, 22, said disk being preferably formed of mica and split, as at 23, to permit it to slip in between the windings of the coil.

In this manner the coil is built up by inserting the mica disks until it has assumed the proper length, whereupon the sleeve 24, of mica or other suitable material, is slipped over the coil and also an inner sleeve 24*is inserted. The top plate 25 is then placed in position and the whole inserted in a tube 26,- preferably formed of steel, and when the parts of the magnet are thus inserted Within said tube the upper and lower edges of said tube are upset, as at 27, so as to bind the parts of the magnet together and hold the upper and lower plates 18 and 25 securely in position. The magnet is thus supported on the split ring 16, and by adjusting the position of said ring on the tube 8 with reference to the position of the armature 29, interposed between the outer tube 8 and the inner tube 11, the arc may be correspondingly lengthened and the lamp made to use more or less current. A thimble 28 is inserted between the inner sleeve 24 and the tube 8, said thimble acting to hold said sleeve in position and shorten the air-gap of the magnet. By this construction of the magnet the coils and interposed disks are securely held together, while at the same time the inclosing tube forms a casing enveloping the entire magnet, and thus greatly increasingits efficienc y. The copper coil and mica disks form the subject of a separate application filed by Albert Schweitzer August 9, 1901, Serial No. 71,460, and I make no claim to this feature of the construction of the coil.

Secured to the lower end of the tube 8 is the collar 30, supporting, by means of screws 33, insulated with porcelain bushings, the guide-plate 31 for the housing 5 and the dashpot 34, with insulating mica disks 59 and interposed. A wire 35 is connected to the screw 33 and passes up to the binding-post 3.

The dash-pot 34, owing to its location, may be of increased area in cross-section over the dash-pots ordinarily used in arc-lamps, and the piston 35 is accordingly also of increased area. This piston 35 is preferably formed of aluminium, which is light and has a slippery surface, and owing to the increased size of the dash-pot it is not essential that the piston 35 fit within the dash-pot with great accuracy, and it preferably does not contact with the wall of the dash-pot, so that said piston may move freely, and at the same time suflicient compression is obtained, owing to the increased area. In this way friction is done away with. This piston 35 is supported upon a plate 36 of the clutch 37, the collar 38 of said clutch being secured to the tube 11. A plate 39 holds the piston 35 in position from above, said plate having the collar 40, which encircles the collar 38, and when in position the collar 38 is compressed or hammered down, so as to lit in the beveled inner face of the collar 40, forming a countersunk connection between the two collars and acting to hold the plate 39 securely in position.

The piston 35 has the enlarged central opening 42, which permits of the lateral move ment of the piston 35 when required, and interposed between said piston and the upper and lower plates 36 and 39 are the insulatingdisks 43, formed of mica or other material having a slippery surface, so that said piston 35 may readily assume any required position laterally by slipping over these interposed disks. Where the piston is formed of aluminium and the disks of mica, a very efiicient construction in this respect is obtained.

The clutch 37 is provided with clutch-ari'ns 44, which are pivoted at 45, the inner ends of said clutch-arms having the curved recesses 46, which conform to the shape of the carbon 14. It is apparent from the above construction that when the piston 35 rises within the dash-pot the arms 44 will bind the carbon and carry the carbon up with the dash-pot, and so form the are between the upper carbon and the lower carbon 47.

The inner globe-cap 48 is connected to the dash-pot 34 by means of the bolts 49, said bolts being pivoted at 49 and passing up between lugs 50 and having the nuts 51 secured thereto. By simply loosening the nuts 51 the bolts 49 may be swung back and the globesupport 48 quickly removed for inspecting the operation of the interior mechanism.

A bushing 52, of suit-ableinsulating material, is supported by the globe-cap 48, the upper carbon 14 passing through said bushing. To the globe-cap 48 are attached the rods 54, supporting the lower-carbon holder 55.

A suitable globe- 56 is secured to the globecap 48 by a spring-holder 66, so as to form a practically air-tight receptacle within which the carbons burn. This globe-holder is composed of a bent steel-wire bail 66, formed with a ring 66, so as to lit the circular bottom of the globe 56, and attached to the lugs on the side of the dash-pot 34 by means of two screws 67 and 67. The ends of the bent steel wire 66 are surrounded by brass tubes 62, in which are coil steel-wire springs 64, acting against nuts and resting on disks 63, screwed in ends of brass tubes 62. The bail is thus adapted to hold the globe up in position and is free to swing to one side when it is desired to remove said globe.

An outer globe 57 incloses the parts, said outer globe being secured to the hood 32 by means of the screws 58. Any suitable switch 68 may be employed for opening and closing the circuit.

\Vhat I claim is 1. In an arc-lamp, the combination with a suitableframe, of an electromagnet supported thereby comprising an upper and lower plate, a spiral conductor composed of a flat strip of conducting material, disks of insulating material between the convolutions of the coil, said conductor and disks being interposed between said plates, a tube inclosing said coil from end to end, and means for retainingsaid upper and lower plates in position,

2. In an arc-lamp, the combination with a suitable frame, of an electromagnet supported thereby comprising an upper and lower plate, a spiral conductor composed of a flat strip of conducting material, disks of insulating material between the convolutions of the coil, said conductor and disks being interposed between said plates, a tube inclosing said coil from end to end, the ends of said tube being upset to engage said plates.

3. In an arc-lamp, the combination with a suitable frame, of an electromagnet supported thereby comprising an upper and lower plate, disks of insulating material between the convolutions of the coil, a sleeve of insulating material inclosing said coil on the outside, a tube inclosingsaid coil from end to end, and means for retaining said upper and lower plates in position.

4. In an arc-lamp, the combination with a suitable frame, of an electromagnet supported thereby comprising an upper and lower plate,

disks of insulating material between the convolutions of the coil, a sleeve of insulating material inclosing said coil on the outside, a second insulating-sleeve inserted within said coil, a tube inclosing said coil from end to end, and means for retaining said upper and lower plates in position.

5. In an arc-lamp, the combination with a suitable frame, of an electromagnet supported thereby comprising an upper and lower plate, disks of insulating material between the convolutions of the coil, said conductor and disks being interposed between said plates, a sleeve of insulating material inserted within said coil, a tube inclosing said coil from end to end, and means for retaining said upper and lower plates in position.

6. In an arc-lamp, the combination with a suitable frame, of an electromagnet supported thereby comprising .an upper and lower plate, disks of insulating material between the convolutions of the coil, said conductor and disks being interposed between said plates, a sleeve of insulating material inserted within said coil, a soft-steel thimble inserted within said coil to hold said sleeve in place and shorten the airgap in said coil, a tube inclosing said coil from end to end, and means for retaining said upper and lower plates in position.

7. In an arc-lamp, the combination with the lamp-frame, of a dash-pot at the lower end of said frame, an inner globe-cap carried by said dash-pot, and supporting means for the globe carried by said cap.

8. In an arc-lamp, the combination with the lamp-frame, of a globe-cap removably secured to said frame, and supporting means for the globe carried by said cap.

9. In an arc-lamp, the combination with the lamp-frame, of an inner globe-cap, outwardlyswinging arms on the globe-cap, means for connecting said arms to the lamp-frame, and supporting means for the globe carried by said cap.

10. In an arc-lamp, the combination with the lamp-frame, of a dash-pot at the lower end of said frame, an inner globecap, outwardlyswinging arms on said globe-cap, and means for connecting said arms to said dash-pot.

11. In an arc-lamp, the combination with the lamp-frame, of a dash-potat the lower end of said frame, a globe-cap below said dash-pot, outwardly-swinging arms on said globe-cap, projections on said dash-pot having recesses formed therein adapted to receive said arms, and means for securing said arms within said recesses. t

12. In an arc-lamp, the combination with the lamp-frame, of a dash-pot at the lower end ofsaid frame, a globe-cap below said dash-pot, outwardly-swinging arms on said globe-cap, said arms having threaded outer ends, projections on said dash-pot having recesses therein with which said arms are adapted to engage, and nuts securedto the outer ends of said arms.

13. In an arc-lamp, the combination with the lamp-frame, of a dash-pot, a piston-rod, a piston adapted to move up and downin said dash-pot and through which the carbon passes, said piston having-an enlarged central opening surrounding said piston-rod, and a disk secured to the piston-rod and on which said piston movably rests.

let. In an arc-lamp, the combination with the lamp-frame, of a dash-pot, a piston-rod, a piston having an enlarged central opening surrounding said piston-rod, and disks secured to the piston-rod and engagingthe opposite faces of said piston in such manner as to permit movement of the latter.

15. In an arc-lamp, the combination with a lamp-frame, of a dash-pot, a piston-rod, a piston having an enlarged central opening surrounding said piston-rod, disks of slippery material engaging the opposite faces of said piston in such manner as to permit movement of the latter, and upper and lower plates secured to the piston-rod and adapted to hold said disks in position.

16. In an arc-lamp, the combination with a lamp-frame, of a dash-pot, a piston-rod, a piston having an enlarged central opening sur rounding said piston-rod, a plate on which said piston movably rests, said plate being secured to said piston-rod and carrying the clutcharms for engaging the carbon, an upper plate secured to the piston-rod, and disks of slippery material interposed between said plates and said piston.

17. In an arc-lamp, the combination with the lamp-frame, of a tube supported therein, a ring engaging said tube, an electromagnet supported by said ring, an armature in said tube, and means for adjusting said ring at dif- IIO ferent heights so as to vary the position of said electromagnet with reference to the armature.

18. In an'arc-lamp, the combination with the lamp-frame, of a tube supported therein, a split ring engaging said tube, an armature in said tube, and an eleotromagnet supported by said split ring.

19. In an arc-lamp, the combination of a movable carbon-holder, and a flexible spiral conductor of thin flat ribbon connected to said holder.

20. In an arc-lamp, the combination with the frame, of a carbon movably mounted therein, and a flexible spiral conductor of thin flat ribbon connected to said carbon.

21. In an arc-lamp, the combination with the frame, of a tube, a carbon movably mounted within said tube, and a flexible spiral conductor of thin flat ribbon connected to said carbon and to a support above.

22. In an arc-lamp, the combination with the frame, of a tube closed at its upper end, a carbon movably mounted in said tube, and a flexible spiral conductor of thin flat ribbon connected to said carbon and the upper end of said tube.

23. In an arc-lamp, the combination with the frame, of a tube, a bushing within said tube adapted to receive the carbon, and a flexible spiral conductor of thin flat ribbon connected to said bushing and to the upper end of said tube.

24. In an arc-lamp, the combination with the frame, of an outer tube, an inner tube, a carbon supported within said inner tube, and a flexible spiral conductor of thin flat resilient ribbon connected to said inner tube and to the upper end of said outer tube.

25. In an arc-lamp, the combination with the frame, of swinging guides extending down therefrom, a bail whose ends enter said guides, and a spring interposed between enlargements on ends of said bail and abutments on said guides.

26. In an arc-lamp, the combination with the frame, of a globe, a bail for supporting said globe, enlargements on the ends of said bail, tubes pivotally connected to the frame and into which said bail ends project, and spiral springs between the enlargements on said bail and the lower ends of said tubes.

In testimony whereof I, the said LAFAYETTE E. SAFFORD, have hereunto set my hand.

LAFAYETTE E. SAFFORD.

Witnesses:

ROBERT C. TOTTEN, F. W. WINTER. 

